tseng:1

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Smart OfficeBluetooth Sensor Network Instant
Messaging

• Y.-C. Tseng, T.-Y. Lin, Y.-K. Liu, and, B.-R.
  Lin, "Event-Driven Messaging Services over
  Integrated Cellular and Wireless Sensor Networks
  Prototyping Experiences of a Visitor System",
  IEEE J. on Selected Areas in Communications,
  2005.

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Motivation Instant Messaging Service

• Instant Messaging and Presence Services
• Short Message Service (SMS) in GSM
• MSN Messenger / ICQ

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Goals of our Event-Driven Messaging Services

• Cross-network applications and services.
• Event driven messaging service
• Modular approach by dividing the system into
  several subsystems according to their
  functionalities.

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Scenario Smart Office

• Bluetooth-based Sensor Network
• Mike???????? ???ready
• ??? ????Mike??, ???????
• ??? ???????? Mike??????office
• (view demo visitor-system-flash.exe)

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System Architecture Overview
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System Architecture (1/2)

• Location Server
• Maintain the user-location mapping in a database.
  
• Action Server
• Carry out action with reliability
• Event Server
• Trigger an action

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System Architecture (2/2)

• SMPP Client and WAP Web Server
• Plays the role as a bridge between telephone
  network and Internet.
• Bluetooth Sensor
• Detects the user location
• Connects with mobile terminals through Bluetooth
• Client
• Bluetooth-enabled laptop/palmtop or a
  Bluetooth-enabled WAP handset.

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Configuration Example 1

• Mike configures an event
• (Alice Enter Sensor X) AND (Bob Enter Sensor X)
  Do Unicast (Mike)
• When the event becomes true, the system will send
  Mike a message.

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Message Flows (through NB)
(Message for Mike, index)
Alice gt X Bob gt X Send to Mike
Alice gt X Bob gt X index of Action
Alice gt X Bob gt X index of Action
Alice gt X Bob gt X
Bob gt X
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When the Event Happening
(Message for Mike, index)
Alice gt X Bob gt X index of Action
Alice gt X Bob gt X index of Action
Bob gt X
Alice and Bob have arrived!
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Configuration Example 2

• Cathy Submits a request On ( Manager LEAVE
  Sensor X 3 ) Do Unicast Cathy through WAP.
• When the event becomes true, the system will send
  Cathy a message

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Message Flows (through WAP)
(Message for Cathy, index)
(Mike lt X)3 Send to Cathy
(Mike lt X)3 Index of Action
Mike lt X
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When the Event Happening
The device of Cathy is a handset
(Message for Cathy, index)
(Mike lt X)3 Index of Action
(Mike lt X)3 Index of Action
(Mike lt X)3 Index of Action
3 min later!!
Mike lt X
Mike is available
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Definition Events and Actions (1/2)

• Events are expressed as the following format
• On lt EvntVal gt Do lt Action gt
• Action
• Unicast, Geocast, Multicast, or Broadcast
• Text or file

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Events and Actions (2/2)

• EvntVal
• Time Event
• Absolute time _at_04/16/04 900
• Relative time (Bob gt Office) 5
• Time interval 04/16/04 900 04/16/04 1100
• Periodical time 04/16/04 900 10
• Location Event
• Enter, Leave and At
• Compound Event
• AND, OR, NOT, (),

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EBNF Grammar of Event Expression

• lt EvntVal gt lt SubEvntVal gt lt EvntVal gt
• lt SubEvntVal gt lt EvntVal gt
  
• lt SubEvntVal gt
• lt SubEvntVal gt lt SnglEvntVal gt (lt EvntVal gt)
  
• ! lt SubEvntVal gt
• lt SnglEvntVal gt lt LocEvnt gt lt TimeEvnt gt
• lt LocEvnt gt lt ID gt lt Rel gt lt Sensor X gt
• lt Rel gt gt lt _at_
• lt TimeEvnt gt lt min/hr/dat/mon/yr gt
• lt TimeOfEvnt(LocEvnt) mingt
• ltmin/hr/dat/mon/yrmin/hr/dat/mon/yr gt
• lt min/hr/dat/mon/yr period gt

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Sensing and Detecting Capability

• A sensing field A with a N sensors. Sensors are
  not synchronized in time.
• The average Latency L the user can be detected
  by any sensor after it appears.
• Ai be the area of A that is covered by exactly i
  sensors. (1 i n)
• Li be the latency such that a user is detected by
  any sensor after it appears in Ai .
• Therefore,

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Sensing and Detecting Example
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Calculation of Li
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Summary of Contributions

• We have prototyped an event-driven instant
  messaging application over integrated telecomm
  and datacomm networks.
• Sensing/detecting capability analysis